Hello so I recently purchased a 2008 x30 with the 6.0l 400. I went in half with my family and they think you can drive it wide open throttle up and down the lake. How bad is this for the engine? In the indmar manual that came with the boat I cannot find it,but in the online pdf from Indmar's website it is there.

I doubt there is technically anything wrong with this...but there is no way I would run my boat flat out all the time. Seems like excessive engine wear for just a few more mphs. I cruise at 30-35. You're in a Mastercraft not a Bayliner, slow down and let people be jealous.